1. Detailed Description of the Invention
The present invention relates to a switch apparatus for a steering wheel, and more particularly to a switch apparatus for a steering wheel for switching an electrical apparatus or the like to be used for an automobile.
2. Description of the Prior Art
With reference to the drawings, the description will be made of a conventional switch apparatus for a steering wheel.
FIG. 5 is a plan view showing the conventional switch apparatus for the steering wheel, and FIG. 6 is a partial enlarged sectional view taken on line 6--6 of FIG. 5.
As shown in FIGS. 5 and 6, a steering wheel 10 is generally constructed of: a substantially annular ring section 1; a pad section 3 disposed in the central portion of the ring section 1; and a spoke section 2 for connecting the ring section 1 to the pad section 3.
This steering wheel 10 is rotatively connected to a vehicle body through a steering shaft (not shown).
In other words, the vehicle body is capable of being turned to the right or the left by operating the steering wheel 10.
On the surface of the pad section 3, a plurality of (for example, two) recesses 3a are provided near the ring section 1. On the bottom wall of the recess 3a, there is provided a rectangular hole 3b respectively. These holes 3b are provided at positions respectively where they are axial symmetrical about the center line of the steering wheel 10.
Within the pad section 3, a switch apparatus 4 having an operating section 4a is disposed by appropriate means in a state connected to a printed circuit board 5. At this time, the operating section 4a of the switch apparatus 4 is disposed such that it protrudes from the hole 3b of the recess 3a outwardly and that the top surface of the operating section 4a is substantially flush with that of the pad section 3.
This switch apparatus 4 is constructed such that when the operating section 4a is depressed (in a direction indicated by an arrow G), the switch apparatus 4 is turned ON, and when the depression of the operating section 4a is stopped, the operating section 4a automatically returns to the original position to turn OFF.
Next, the description will be made of an operation of the switch apparatus for the steering wheel.
First, when an operator (for example, driver of the vehicle) depresses the operating section 4a of the switch apparatus 4 with, for example, his or her thumb with the ring section 1 of the steering wheel 10 grasped by hands, the switch apparatus 4 is turned ON, and when the depression of the operating section 4a with the thumb is stopped, it is turned OFF.
By such an operation, the switch apparatus 4 is turned ON or OFF, and for example, selected station for a radio receiver, setting of auto-cruising, muting of an acoustic apparatus and the like can be switched.
In the conventional switch apparatus for the steering wheel, however, since the ON-OFF operation of the switch apparatus 4 is performed only by depressing the operating section 4a, the switch apparatus 4 is to be operated by the thumb in a state in which the ring section 1 is grasped by hands, and accordingly, there is no degree of freedom, but there arises demand to increase the degree of freedom in view of operation.